Process and apparatus for making sheet glass



March 5, 1929. CANNON 1,704,552

- PROCESS AND APPARATUS .FOR' MAKING SHEET GLASS Filed Dec.. 14; 1927 Sheets-Sheet '1 1a 1 F" .1. 1Z\

15 J L; fi J r 1 j I 10H l l I l INVENTOR Patented Mar. 5, 1929.. I

UNITED STATES.-

nomr rc F. cANNoN, 0]? FORD CITY, PENNSYLVANIA. ASSIGNOR 'ro PITTSBURGH PLATE eLAss ooMPANY, A coRPoRA'rIoN or PENNSYLVANIA.

PROCESS AND APPARATUS FOR MAKING SHEET GLASS.

Application filed December 14, 1927. Serial No. 239,903.

in a rolling machine of the particular type illustrated in the patent. It has for its principal object the provision of means for supporting and. guiding the leading edge of the sheet onto and over the runway when the rolling operation is started, although the apparatus may also be used as a cooling device after the rolling operation is underway. At the beginning of the rolling operation, the leading edge of the sheet has a tendency to turn downward and catch upon the forward edge of the cooling platen, and after such edge has passed over the platen, it still tends, due to its plastic condition, to turn downward between the rolls of the runway. The same difficulty obtains in those cases in which the first member of the runway consists of a roll instead of the platen. This condition has heretofore been taken care of by the use of hand tools,.such as bars or rods, and by the use of various other devices, such as plates which move. along under the advancing end of the sheet and support it until it has hardened, so that it will not turn down and catch, but none of these expedients has proven entirely satisfactory and the present invention is de signed .toaccomplish the desired function with greater certainty and with less care and effort on "the part of the operators. Briefly stated, this is preferably accomplished by the use of air blasts, which are so directed that they turn the advancing plastic end of the glass sheet up slightly and hold it up and harden it while it is advancing over theforward end of the receiving platen. The fluid preferably employed to lift the end of the sheet is air, but other gaseous fluids may be employed, such as steam. One form of apparatus for carrying out the invention is shown in the accompanying drawings, wherein:

Figure 1 is a plan View of the apparatus with the upper sizing roll removed. Fig. 2 is'a section on the line II-II of Fig. 1 with the upper sizing roll in position. And Fig. 3 is a view similar to Fig. 2, but on an enlarged scale.

Referring to the drawings, 1 "is the large sizin roll supported upon the driven rollers 2 and 3, and 4: is the upper sizing roll also driven and suitably water cooled. The glass to be rolled into a sheet is teemed into the space between the rolls, as indicated at 5 and the sheet 6 which is formed first passes onto the apron 7, forming the first element .of the runway and then over the rolls 8, which lead into the annealing leer, not shown. v

The device for preventing the sheet from catching upon the forward edge 9 (Fig. 3) of the platen or apron 7 comprises the transverse air pipe 10, to which are connected the supplemental pipes 11, 12, 13, etc. by means of the connections 14. The pipes 11, 12 and 13 are perforated along their sides, which lie next to the roll 1, as indicated at 1 1 in Fig. 3, so that when air pressure is supplied through the pipe 10, the air blasts 15 are applied to the surface of the roll 1 just above the apron 7. These blasts are ap lied at an angle, as indicated at Fig. 3 an are of such force that they lift the forward edge of the sheet slightly, so that when this edge reaches the end 9 of the apron, itis elevated so that it will not catch upon such end. The air blasts also have a cooling effect upon the end of the sheet which reduces its tendency to turn downward and engage the end of the apron 7. After the edge of the sheet has passed the end 9 of the apron, the flow of air through the pipe. 10 is shut off by means of the valve 16 and the operation is continued in the usual way. As indicated in Fig. 1, the end pipes 11 of the series are inclined with respect to the other pipes to give a better lifting effect upon the curved portions of the sheet adjacent its side edges. Various other arrangements might obviously be provided for accomplishin the function of cooling the advance edge 0 the sheet and lifting it slightly, the invention not being limited to the particular arrangement shown or to the particular angle illustrated for applying the air blasts, although this is the arrangement which is preferred.

What I claim is:

1. A process for holding up the advance edge of a plastic sheet of glass as it passes from a forming roll onto a runway which consists in applying a blast of fluid between the forming roll and the advancing end of the sheet to lift such end as it passes onto the end of the runway. f

2. A process for holding up the advance edge of a plastic sheet of glass as it passes from a forming roll onto a runwa which consists in directing a blast of flui toward rection C(ffiOSltB tot at of the advance of the sheet an etwee'n the end of such sheet and the roll soas to lift such end during its passage over the forward end of the runway.

4. In combination in apparatus for making sheet glass, including a pair of rolls between which the glass is sized or rolled to the desired thickness, a runway for receiving the glass from the lower roll. and means for directing a blast of fluid beneath the advancing end of the sheet reliminary to its movement over the end 0 the runway.

5. In combination in apparatus for making sheet glass, including'a pair of rolls between WhlCh the glass is sized or rolled to the desired thickness, a runwa for receiving the glass from the lower r0 1, a pipe extending transversely of the roll adjacent the end of the runwa and openin toward the surface of the rol and means or supplying fluidunder pressure to the pipe to provide a blast of fluld toward the advancing end of the sheet.

6. In combinationin apparatus for making sheet glass, including a pair of rolls between which the glass is sized or rolled to the desired thickness, a runwa ing the glass from the lower ro l and means for directing a blast of fluid toward the advancing end of the sheet and against the surface of the roll to chill such end of the sheet and force the fluid therebeneath. A

In testimony whereof, I have hereunto subscribed my name this 29th day of November, 1927.

' DOMINIC F. CANNON.

for receiv-* 

